Device and method for producing tubular packs that are filled with a product

ABSTRACT

A device for producing a tubular pack which is filled with a product, particularly with a foodstuff, comprises a conveying device for conveying a tube filled with the product. A closing device is provided for producing tubular packs. This closing device comprises pinching elements, which can be moved toward one another and which serve to press a closing clasp together that closes the tube. According to the invention, the closing device comprises at least three pinching elements that can be displaced by a displacing element. This results in the exertion of pinching forces, which are directed in a radially inward manner, by the pinching elements onto the closing clasp.

FIELD OF THE INVENTION

The invention relates to a device for producing tubular packs which arefilled with a product, particularly with a foodstuff and chemicalproducts (silicones, adhesives, explosives). Such tubular packs areused, for example, for packing spreadable sausage and the like. Further,such tubular packs are suitable for packing chemical products,particularly silicones and adhesives, as well as for packing explosives.

DISCUSSION OF THE BACKGROUND ART

Conventionally, tubular packs are filled with the respective product andclosed with a closing clasp of metal at regular intervals. The tubularpack is an endless material so that the closing clasps are arranged suchthat between two successive closing clasps, a tubular pack filled with aproduct and an empty tubular section are alternately configured. Toproduce a single tubular pack filled with a product, the tubular pack isseparated by cutting in the empty section after it has been closed withclosing clasps.

A device for producing tubular packs filled with a foodstuff isdescribed in DE 40 11 470 A1. For closing the individual tubular packs,closing clasps consisting of a flat metal piece are used. The metalpiece, which is rectangular in the non-deformed state, is laid about thefilled tubular pack and closed by a closing device. By means of theclosing device, the closing clasp is bent and pressed together from twosides so that a flat closing clasp is created. The ends of the closingclasp overlap each other to avoid that the product in the tubular packescapes. Thus, the closing clasp known from DE 40 11 470 A1 issubstantially rectangular in the closed state, the force required forclosing being exerted upon the tubular pack by the two opposite longersides.

Such closing clasps suffer from the disadvantage that tightness problemsdo often occur, particularly because of the ends of the closing claspsoverlapping each other. This leads to the fact that the products do notkeep well and the products have to be stored in refrigerating shelves.Another disadvantage consists in that the described device is only ableto process closing clasps of a certain size. This results in that onlytubular packs within a small diameter range can be processed. Theprocessable dimensional variations are very small. Further, it isdifficult to process different packaging materials if they differ inmaterial thickness and thus, a different amount of material appears inthe bundled state at that site where the closing clasp is arranged. Thisleads to tightness problems very often. To be able to process differenttubular packs by this device, high modification efforts are required.

It is an object of the invention to provide a device for producingtubular packs that are filled with a product, by means of whichdifferent tubular packs can be closed. Further, it is an object of theinvention to provide a corresponding method.

SUMMARY OF THE INVENTION

The object is solved, according to the invention, by a device accordingto claim 1 and a method according to claim 19.

The device for producing tubular packs filled with a product accordingto the invention comprises a conveying device for conveying a tubefilled with a product, a closing device for closing the tube as well aspreferably a cutting means for disconnecting individual or severalinterconnected tubular packs. The closing device comprises pinchingelements which can be moved toward one another for pressing together aclosing clasp that closes the tube. The individual closing clasps arepreferably arranged such that a tubular pack filled with a product andan empty tube section alternate each other between closing claspssucceeding each other in conveyance direction. The separation of thetube filled with a product into individual tubular packs is thenpreferably effected by the cutting means, the cutting means separatingthe tube at the empty tube section. According to the invention, theclosing device is configured such that at least three pinching elementsare provided. The pinching elements are displaced by a displacingelement in such a manner that they exert pinching forces onto theclosing clasp which are substantially directed radially inward.

Due to the substantially radial displacement of the pinching elements,approximately uniformly and circumferentially distributed radial forcesact on the tube in the region of the closing clasp. Thereby, aconsiderably greater tightness of the closure is ensured. This resultsin that the product in the tubular pack keeps much better. Thereby, itis also possible, in case of packed food, to keep it over an elongatedperiod of time outside of refrigerating shelves.

Further, it is possible to set the substantially radial displacement ofthe pinching elements. Thereby, the circumference of the crimped closingclasp can be varied. To this end, in case of a closing clasp consistingof a metal wire, for example, it is only required to provide a piece ofwire of corresponding length which is then formed into a triangle whileusing three pinching elements. Since the closing device according to theinvention is able to simply realize different circumferences of theclosing clasps in the crimped state, no labor-intensive modification ofthe closing device is necessary to be able to close, e.g., tubular packswith different outer diameters and thus with different material amountsto be closed. Differences in the package thickness, for which differentclosing clasps are necessary as well, can also be easily set and thusbalanced by the device according to the invention.

By the use of three pinching elements, the closing device according tothe invention produces a triangular closing clasp in the crimped state.Preferably, six and particularly preferably, eight pinching elements areprovided. Thereby, a hexagonal or octagonal closing clamp is produced inthe crimped state so that the tightness of the closing site is furtherincreased. Due to the shape of the closing clasp approaching that of around closure, it is further not required that the ends of the closingclasp overlap each other.

Each of the individual pinching elements may be connected with adisplacing element by which a substantially radial movement of thepinching elements is realized. Preferably, the displacing elements aredisplaced by means of a common worm drive.

Preferably, the displacing element or several displacing elements areconnected such with the pinching elements that the pinching elements aredisplaced in radial direction by moving or actuating the displacingelement(s). It is particularly preferred to provide one or moredisplacing elements, the radial displacement of the pinching elementsbeing caused by turning the displacing element(s). In this case, it isparticularly preferred to provide a single, preferably annular,displacing element for all pinching elements. Preferably, the displacingelement is connected with the pinching elements via pins or lugs andcorresponding slots.

In a preferred embodiment, the closing device is configured in themanner of an iris diaphragm. In this case, the individual pinchingelements are connected with the displacing element such that thepinching elements are displaced in substantially radial direction byrotating the displacing element. In the closing device configured in themanner of an iris diaphragm, the pinching elements are additionallyrotated, if necessary. This is irrelevant with respect to the radiallydirected pinching forces. Upon closing the iris diaphragm, the closingclasp is bent and/or pressed together. Before the iris diaphragm isclosed, the closing clasp may be a straight piece of wire, particularlyflattened wire. Further, the closing clasp may already be pre-bent.

Preferably, the closing device in the manner of an iris diaphragm isconstructed such that the displacing element to be rotated compriseslugs or slots and that each lug and slot, respectively, engages into aslot and lug provided in the transverse element, respectively. Byrotating the closing element, the lugs glide in the slots. Thereby, thepinching elements are radially displaced. Thus, the opening of the irisdiaphragm-like closing device depends on the degree of rotation of thedisplacing element. The farther the displacing element is rotated, thesmaller is the opening of the iris diaphragm. This results in that thepinching forces linearly increase when the iris diaphragm opening getssmaller.

Preferably, the pinching elements are arranged in one plane. This hasthe advantage that a jamming or tilting of the closing clasp during theclosing procedure is avoided.

Likewise, it is also possible to provide pinching elements in the shapeof annulus segments or kidney-shaped pinching elements. Depending on theshape of the pinching elements, an approximately round deformation ofthe closing clasp can be effected. Thereby, a very tight sealing of thepackage is realized. Such pinching elements preferably overlap eachother partially and therefore, they are arranged in different planes.Likewise, it is also possible to arrange the individual pinchingelements so as to be slightly inclined towards each other so that aniris diaphragm-like closure is realized again and preferably, eachsingle pinching element is in turn connected with a common rotatabledisplacing element again.

In a preferred embodiment of the device according to the invention, asevering means is provided. The severing means serves to severe theclosing clasp, which is configured as an endless material, particularlyas an endless wire. By means of the severing means, the endless materialis cut into corresponding lengths. The length depends on the diameter ofthe tube filled with the product as well as on the material thickness ofthe tube. Preferably, the severance is effected so as to form a lengthwhere an overlapping of the ends of the closing clasp is avoided. Sinceit is known how far the pinching elements of the closing clasp are movedtowards each other, i.e., how large the remaining opening is, the lengthof the closing clasps is preferably selected such that the two endsexactly contact each other when the closing clasp is crimped together.Thereby, an extremely tight sealing of the tubular pack is possible.

The length of the endless material to be severed may be set, e.g., by astop. Further, it is possible to set the length to be severed due to thewire advance relative to a severance site of the severing means. In thiscase, the wire advance is effected preferably electrically.

In a particularly preferred embodiment, one of the pinching elements isconfigured as a severing means. To this end, the corresponding pinchingelement may comprise a cutting edge so that a severing of the endlessmaterial is effected preferably directly upon the radial displacement ofthe corresponding pinching element. The severing and subsequent pressingtogether of the closing clasp is thus preferably effected in oneoperational step.

Further, the invention relates to a method for producing tubular packswhich are filled with a product, particularly with a foodstuff. Theafore-described device is particularly well suitable for performing themethod. During the method, a tubular pack filled with a product issupplied to a closing device. Preferably, this is a continuousconveyance of the tube filled with a product. Further, a closing claspis supplied to the closing device with at least three pinching elementssurrounding the tubular pack. In the next step, the pinching elementsare displaced in substantially radial direction in such a manner thatthe pinching elements exert radial pinching forces upon the closingclasp. In the last step, successive tubular packs are then produced byseparating the tubular pack between two closing clasps succeeding eachother in the direction of conveyance.

Preferably, for closing the tubular pack, the pinching elements aresubstantially displaced in radial direction by rotating a displacingelement connected with the pinching elements. It is also possible toprovide several displacing elements to this end. It is preferred,however, to provide a single displacing element for all pinchingelements so that all pinching elements are displaced, particularlyradially inward in a uniform manner, by simply rotating a displacingelement. Thereby, a uniform force is exerted upon the closing clasp.

Preferably, successive closing clasps are provided such at the tube thata tubular pack filled with a product and an empty tube section arealternately configured between two closing clasps succeeding each otherin the direction of conveyance. Preferably, the tubular pack isseparated between two closing clasps within the empty tube section.

It is particularly preferred to supply an endless material, particularlyan endless wire, to the closing device and to severe the endlessmaterial to form the closing clasp. By using endless material as aclosing clasp, an extremely variable method has been provided as to thecircumference of the closing clasp in the crimped state, where thiscircumference can be changed in a simple manner.

With the method according to the invention, such a pinching force isgenerated that the packaging material bonds to itself in the region ofthe closing clasp. If the packaging material is plastic, a fusion of thepackaging material can be achieved thereby. Thereby, the tightness ofthe tubular pack at the closing site is considerably improved.Particularly with plastic material, a completely tight bonding of thepackaging material can be effected. This can be done exclusively byincreasing the pinching forces. It is also possible to additionallysupply the closing region with heat instead of increasing the pinchingforces. To avoid an impairment of the food by the heat, it is possibleto supply heat exclusively to the closing clasp itself if it consists ofa heat-conducting material such as metal.

In dependence on the transport speed of the sausage tube, it is possibleto move the closing device together with the tube in the direction oftransport thereof during the pinching procedure. Thereby, a secureclosing is achieved. Particularly if heat enters, a closing devicemoving along with the tube is advantageous. Preferably, the tube istransported in vertical direction. This has the advantage that the tubecan be held so as to suspend freely within the closing device. In thiscase, the closing device is preferably arranged horizontally. The factthat the closing device moves along with the tube has the advantage thata continuous transport of the tube filled with a product can beeffected. Therefore, no “stop-and-go” operation for closing the tubularpack is required.

Hereinafter, the inventions are explained in detail with respect to apreferred embodiment with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the Figures:

FIG. 1 shows a schematic, partially sectioned side view of the deviceaccording to the invention,

FIGS. 2-5 schematic plan view onto the closing device in differentpositions, and

FIG. 6 a schematic sectional view along the line VI—VI in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Within a filling means 12, a tube 10 is filled with a product,particularly a foodstuff. Thereby, a well-filled tube 14 is producedwhich has to be divided into individual tubular packs 16. The ends 18,20 of the tubular pack 16 are respectively closed by a closing clasp 22.In order to mount the closing clasps 22, two closing devices 24 areprovided in the illustrated embodiment, which are arranged at a smallhorizontal mutual distance and tighten up the filled tube 14, crimp itand close it by means of the closing clasp.

Between the two closing devices 24, an empty tube section 26 or one atmost slightly filled with a product is formed. At the empty tube section26, the filled tube 14 is separated by means of a cutting means 28.

The closing device comprises several pinching elements 30, 33, 34, 36,38, 40 (FIG. 2) which are displaceable via a displacing element 42. Thedisplacing element 42 has to be rotated in the direction of an arrow 44in order to displace the pinching elements 30-40. The drive of the twoclosing devices 24 illustrated in FIG. 1 and the displacing elements 42provided therefor (FIG. 2) is effected via a motor 46 which, e.g.,engages with the displacing elements 42 via gears 48 or the like.Likewise, a cam disc or the like may be provided for driving thedisplacing elements 42.

The movement of the pinching elements 30-40 can be seen in FIGS. 2-5. Tothis end, the substantially annular displacing element 42 comprises sixpins 50 in the illustrated embodiment. The pins 50 are arranged atregular distances at the annular displacing element 42. Each pin or lug50 protrudes into a slot 52, respectively. Each pinching element 30-40comprises a slot 52. When the displacing element 42 is rotated in thedirection of the arrow 44, the lugs or pins 50 glide into the slots 52.Thereby, the movements of the pinching elements 30-40 to be seen inFIGS. 2-5 are effected.

To avoid a co-rotation of the pinching elements 30-40 when thedisplacing element 42 is rotated, the pinching elements 30-40 arearranged in a hexagonal recess 54 in the illustrated embodiment. Thehexagonal recess 54 comprises six inner edges 56, a narrow side 58 ofthe pinching elements 30-40 respectively contacting an inner edge 56.When the displacing element 42 is rotated in the direction of the arrow44, the side faces 58 of the pinching elements 30-40 glide at theinsides 56 of the opening 54 in the direction of an arrow 60 (FIG. 3).

Since the pinching elements 30-40 are arranged in a plane, neighboringpinching elements glide along narrow sides 62 and 64 contacting eachother, respectively, when the displacing element 42 is rotated. With itsnarrow side 54, the pinching element 32, for example, glides along along narrow side 62 of the pinching element 30 in the direction of anarrow 66. A corresponding movement is also performed between the otherneighboring pinching elements 30-40.

To avoid a jamming of the pinching elements 30-40, a narrow side 62comprises a guiding projection 70 (FIG. 6). The guiding projection 70engages into a guiding groove 72 provided in the narrow side 62 of theneighboring pinching element 38.

The closing clasp 22 consists of a bendable wire. Depending on therequired length of the closing clasp 22, the latter is cut from anendless wire 74. The length of the closing clasp 22 depends on therequired closing position (FIG. 5). The latter depends on the amount oftube material which is to be enclosed by the closing clasp. The metalwire 74 from which the closing clasp 22 is cut is led into the hexagonalinterior space 78 formed by the six pinching elements 30-40 via a bore76 provided in the pinching element 30. By a corresponding advance ofthe wire 74 or by a corresponding stop, the required length of theclosing clasp 22 is determined. By moving the pinching element 32 in thedirection of the arrow 66 (FIG. 3), the closing clasp 22 is cut off. Tothis end, the narrow side 62 of the pinching element 32 pointing in thedirection of the opening 78 is configured as a cutting edge in theregion where the cutting of the wire 74 is effected.

For not having to extract the wire 74 completely from the transversebore 76 in order to permit a movement of the pinching elements forpinching the closing clasp, a slot 80 (FIG. 6) is provided in thepinching element 40 adjacent the pinching element 30, which serves toreceive the wire 74 when the pinching elements 30-40 are displaced intothe positions illustrated in FIGS. 2-5.

1. A device for producing tubular packs that are filled with a product,particularly with a foodstuff, comprising a conveying device forconveying a tube filled with the product, and a closing device forclosing the tube, with pinching elements which can be moved toward oneanother for pressing a closing clasp together that closes the tube,wherein the closing device comprises at least three pinching elementsthat are displaceable by a displacing element in such a manner that thepinching elements exert radially inward directed pinching forces ontothe closing clasp relative the tube center, and wherein each pinchingelement comprises a narrow side that glides in contact with aneighboring narrow side of a neighboring pinching element.
 2. The deviceaccording to claim 1, wherein the pinching elements are arranged so asto be radially displaced.
 3. The device according to claim 1 wherein thedisplacement of the pinching elements is effected by rotating thedisplacing element.
 4. The device according to claims 1, wherein theclosing device is configured in the manner of an iris diaphragm so thatthe pinching elements are displaced by rotating the displacing element.5. The device according to claims 1, wherein the displacing elementcomprises lugs or slots, each lug and slot, respectively, engaging intoa slot and lug, respectively, which are provided in each pinchingelement so that the lugs glide in the slots when the displacing elementis actuated.
 6. The device according to claims 1, further comprising atubular pack filled with a product and an empty tube section arealternately formed between closing clasps succeeding each other inconveyance direction.
 7. The device according to claim 6, furthercomprising a cutting means for separating the tube at the empty tubesection.
 8. The device according to claim 1, wherein the pinchingelements are arranged in one plane.
 9. The device according to claim 1,wherein said narrow side comprises a guiding groove into which a guidingprojection of the neighboring narrow side engages.
 10. The deviceaccording to claims 1, wherein the pinching elements have the shape ofan annulus segment or are kidney-shaped.
 11. The device according toclaims 1, wherein the pinching elements are arranged in several planesparallel to each other.
 12. The device according to claims 1, whereinthe pinching elements are arranged such that the closing clasp istriangular or hexagonal in the crimped state.
 13. The device accordingto claims 1, further comprising a severing means for severing theclosing clasp supplied as endless material.
 14. The device according toclaim 13, wherein one of the pinching elements is configured as asevering means.
 15. The device according to claim 13, wherein one of thepinching elements comprises a supply channel for supplying the endlessmaterial.
 16. The device according to claims 6, further comprising twoclosing devices are arranged behind each other in conveyance directionin such a manner that the empty tube section is arranged between the twoclosing devices.
 17. The device according to claim 7, wherein thecutting means is arranged between the two closing devices.
 18. A methodfor producing tubular packs that are filled with a product, particularlya foodstuff, with the steps of supplying the tubular pack filled with aproduct to a closing device, supplying a closing clasp to at least threepinching elements of the closing device which surround the tubular pack,displacing each of the pinching elements in radial direction so thatradial pinching forces are exerted onto the closing clasp by thepinching elements, by gliding each pinching element in contact with aneighboring pinching element, and separating the tubular pack betweentwo closing clasps succeeding each other in conveyance direction. 19.The method according to claim 18, wherein the pinching elements aredisplaced by rotating a displacing element connected with the pinchingelements.
 20. The method according to claim 18, wherein a tubular packfilled with a product and an empty tube section are alternately formedbetween two closing clasps succeeding each other in conveyancedirection.
 21. The method according to claim 18, further comprising anendless material is supplied to the closing device and the endlessmaterial is severed to form the closing clasp.
 22. The method accordingto claim 21, wherein the endless material is severed in dependence onthe circumference of the closing clasp in the crimped state.
 23. Themethod according to claim 22, wherein the endless material is severedsuch that the ends of the closing clasp do not overlap each other in thecrimped state.
 24. The method according to claim 18, wherein such apinching force is generated that the packaging material bonds to itself.